Improvement in step-ladders



J. C. BLAUVELT.

STEP-LADDER.

No.175,Z'14. I Patented April 18, 1876 ATTORNEYS.

N-PETERS, PHOTO-UTNOGRAPNER. WASHINGTON, D Q

i UNITED STATES PATENT Orrrcn.

JOHN CALVIN BLAUVELT, or BLAUVELTVILLE, NEW YORK.

IMPROVEMENT IN STEP-LADDERS.

Specification forming part of Letters Patent No. 176,214, dated April18, 1 876 application filed March 13, 1876.

To all whom it may concern:

Be it known that I, JOHN (J. BLAUVELT, of Blauveltville, in the countyof Itockland and State of New York,.have invented a new and usefulImprovement in Step-Ladders, of which the following is a specification:

Figure 1 represents my improved step ladder folded. Fig. 2 is alongitudinal section of the same, taken through the line a: m, Fig. 1.Fig. 3 is .a horizontal section of the same, taken through the line y 1Fig. 1. Fig. 4 is a longitudinal section of the same arranged for use asa step-ladder. Fig. 5 represents the same extended. for use as a ladder.Fig. 6 is a side view of the same, partly in section, through the line 22, Fig. 5.

Similar letters of reference indicate corresponding parts.

The object of this invention is to furnish an improved step-ladder,which shall be so constructed that it may be readily adjusted for use asa ladder without its being necessary to turn it away from the wall orother object, extend it, and then turn it back, and which shall besimple in construction, and strong, durable, reliable, and safe in use.

The invention consists in the plate and its slot and pins, the circlewith its lugs and notches, the plate with its opening, theconcavo-convex plate with its shoulders, and the stop and the pin, incombination with each other and with the parts of a step-ladder, ashereinafter fully described.

A represents the front part, and B the rear part, of a step-ladder,which are constructedin the usual way. (3 is a plate, attached to theupper end of the rear part B of the stepladder, in line with its innerside, and which has a semicircular projection formed upon its upperpart. In the projection of the plate 0 is formed a short slot, 0extending upward from the center of the circle, of which said projectionis a part, to receive the pivot or bolt 01, that pivots the rear part Bof the ladder to the center of the circular plate D. Upon the rear sideof the circle D are formed, or to it are attached, lugs E, by which itis pivoted to the plate F, attached to the inner side of the upper endof the part A of the ladder, so that the upper part of the said circle Dmay swing through a semicircular opening in the said plate F until itsrearward movement is limited by the stop Gr, attached to the under sideof the top step of the said part A of the ladder. H is apoint or pinattached to the under side of the top step of the part A, at such adistance in front of the stop G as to receive the upper edges of thecircle D and plate 0 between it and the said stop G. In the upper edgeof the circle D is formed a notch, (P, to pass over the pin H, and toreceive the pin 0 attached to the lower part of the plate 0. In thelower edge of the circle D is formed a notch, 01 to receive the said pin0 To the end parts of the plate 0 are attached two pins, 0 made withflat heads, one or the other of which, when the ladder is beingadjusted, moves along the convex rabbeted upper edge of the plate I,attached to the plate F, with its head overlapping the rear side of thesaid edge, and both of whiclnwhen the ladder is extended, rest uponshoulders 6, formed upon the ends of thesaid plate I. The pin 0 when theladder is being adjusted, moves along the concave lower edge of theplate I. To the end part of the plate F, near its lower edge, areattached two pins, f, made with flat heads, to interlock with the headsof the pins 0 when the ladder is folded, and the pin d is in the lowerpart of the slot 0, to prevent the parts A B from separating when thefolded ladder is being carried.

To open the ladder for use as a step-ladder, the part B is drawndownward, bringing the pin al into the upper part of the slot 0,withdrawing the pin 0 from the lower notch d of the circle D, andunlocking the heads of the pins 0 f. The lower end of the part B is thenswung outward until the upper part of the circle D strikes the stop G.The part B is then slid upward, bringing the upper edge of the plate 0behind the plate, bringing the pin d into the lower end of the slot 0,and bringing the pin 0 into the lower notch d of the circle D.

In adjusting the step-ladder as an extensionladder, the part B isdrawndownward to unlock it, is moved inward parallel with the part A, and isthen swung around laterally, upon the pin (1 as a pivot, through half arevolution, and slid downward, bringing the pins 0 upon the shoulders iof the plate I, and bringing the pin 0 into the upper notch of thecircle D, which locks the parts A B securely in place.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- The plate 0 and its slot 0 and pins 0 0 the circle D,with its lugs E and notches 61 (1 the plate F, with its opening, theconcavo-convex plate I, with its shoulders i, and the stop G and pinH,in combination with each other and with the parts A B of astep-ladder, substantially as herein shown and described.

JOHN CALVIN BLAUVELT.

. Witnesses:

A. T. BLAUVELT, M. A. BLAUVELT.

